Mastering Assembly Programming

Arrays of words, double words, and quad words

The previous simple example illustrates a trivial byte array and how we can access its members. The same would apply to arrays of words, double words, or quad words with a few additions:

• We cannot use XLAT on arrays bigger than 256 bytes, nor if members of an array are bigger than 8 bits
• We would need to use SIB addressing (scale index base) in order to access array members bigger than one byte
• On 32-bit systems we would not be able to read a quad word into a single register

For the sake of a simple example, let's consider using a lookup table for the calculation of the factorial for numbers in the range of 0 to 12 (this code is for 32-bit and factorials of larger numbers would not fit into ...